He was monologue-ing through the entire comic about how decrepit and debilitating his body was and cursing how much better the young cops had it. It wasn't tossed aside instantly like TDKR's knee injury was.

I may have to go reread but, if I remember correctly, doesn't he stop monologue-ing about it around the point where he slaps on the leg and arm brace before going to fight the Mutant Leader?